FIELD OF THE INVENTION
The present invention relates to catalytic compositions consisting of beta zeolite (as such or modified) and a ligand, characterized by particular porosity characteristics, which can be used in processes for the alkylation of aromatic hydrocarbons with light olefins, in particular benzenes with C.sub.2 -C.sub.4 olefins and more specifically benzene with ethylene to give ethylbenzene and benzene with propylene to give cumene. The catalytic composition of the present invention can also be used in the transalkylation of aromatic hydrocarbons with polyalkylated aromatic hydrocarbons, especially benzene with diethylbenzene, and possibly triethylbenzene, to give ethylbenzene and benzene with diisopropylbenzene, and possibly triisopropylbenzene, to give cumene.